CHESAPEAKE, Virginia (CNN) --Teenage sniper suspect Lee Boyd Malvo said John Muhammad planned to shoot as many as five children at the Bowie, Maryland, middle school the morning of October 7, 2002, a defense psychiatrist testified at Malvo's trial Thursday.

"Muhammad's plan was to possibly shoot between three and five children, not to kill them, no head shots," psychiatrist Neil Blumberg testified. The idea was to have "a ripple effect," Blumberg quoted Malvo as saying.

One person -- 14-year-old Iran Brown -- was shot at the school. Brown survived his critical injuries and spent more than a month in the hospital.

Malvo told the psychiatrist that Muhammad was the shooter and that he was the spotter. That account contradicts Malvo's statement to police months earlier.

Malvo said he lied to police to spare Muhammad from the death penalty, Blumberg testified.

The psychiatrist said Malvo's account was credible because Malvo acknowledged involvement in all of the sniper shootings and admitted being the shooter in one, the October 22, 2002, shooting of bus driver Conrad Johnson in Aspen Hill, Maryland.

He also admitted to killing Keenya Cook in Tacoma, Washington, in February 2002, Blumberg said.

Fairfax County prosecutor Robert Horan Jr. questioned whether Malvo admitted to shooting Johnson and Cook to avoid facing the death penalty. Maryland and Washington do not allow execution of people convicted of crimes committed as juveniles, while Virginia does.

"Do you think he was smart enough to know ... that he couldn't get the death penalty in Maryland for shooting Conrad Johnson?" Horan asked.

Blumberg said Malvo could have been aware of that, but that he did not believe it affected Malvo's statements.

Horan then asked Blumberg if Malvo knew he couldn't face the death penalty in Washington state.

"I don't know if he knew about that," Blumberg said.

Malvo, now 18, is being tried in the killing of Linda Franklin at a Home Depot in Fairfax County, Virginia, on October 14, 2002. Her death was one of 10 fatal sniper attacks that terrified Washington, D.C., and outlying areas. Three people were wounded in other attacks.

Prosecutors are challenging the defense argument that Muhammad indoctrinated Malvo. Blumberg and other defense experts have testified that during the shootings, Malvo did not know right from wrong and was legally insane, as defined under Virginia law.

In court Thursday, Horan listed the sniper shootings, asking Blumberg what Malvo told him about each crime.

Concerning the shooting at the middle school, Blumberg testified that Malvo told him Muhammad decided to shoot someone at a school in a different area from earlier shootings.

Malvo "told me he didn't like the idea but Muhammad said, 'Let's do it.' He went along with it," Blumberg testified.

"There was good concealment. They had gone there the day before on recon [reconnaissance]. There were three potential schools in that area."

In testimony Wednesday, Blumberg said he spent about 50 hours meeting with Malvo on 20 different occasions following his arrest.